COveRs to impRove EsthetiC ouTcome after Surgery for Chronic subdural hemAtoma by buRr hole trepanation-Results of a Swiss Single-Blinded, Randomized Controlled Trial.

Background And Objectives: Burr hole trepanation to evacuate chronic subdural hematoma (cSDH) results in bony skull defects that can lead to skin depressions. We intend to study the effect of burr hole covers to prevent skin depressions and improve the esthetic result.

Methods: In a randomized trial, we enrolled adult patients with symptomatic cSDH. Patients received burr hole trepanation with (intervention) vs without burr hole covers (control) in a 1:1 ratio. Patients requiring evacuation of bilateral cSDHs served as their internal control. Primary outcome was satisfaction with the esthetic result of the scar, measured from 0 (dissatisfied) to 10 (very satisfied) on the Esthetic Numeric Analog (ANA) scale at 90 days. Secondary outcomes included ANA scale, rates of skin depression, complications, as well as neurological, disability, and health-related quality of life outcomes until 12 months.

Results: We included 78 patients (55 with unilateral and 23 with bilateral cSDH; median age 78 years, 83% male) between 03/2019 and 05/2021, 50 trepanations for the intervention and 51 for the control group. In an intention-to-treat analysis, the ANA scale scores were 9.0 (intervention) and 8.5 (control arm) at 90 days (P = .498). At 12 months, the ANA scale scores were 9.0 and 8.0 for the intervention and control groups, respectively (P = .183). Skin depressions over the frontal burr hole were noted by 35% (intervention) and 63% (control) of patients at 90 days (P = .009) and by 35% and 79% (P < .001) at 12 months, respectively. There were no differences in complications, neurological, disability, and health-related quality of life outcomes.

Conclusion: Satisfaction with the esthetic result of the scar was inherently high. This study does not show evidence for improvement on the ANA scale by applying a burr hole cover. The application of burr hole covers resulted in less skin depressions and did not negatively affect complication rates or outcomes.